A known sewing machine of the type is disclosed in, say, JP3021041U. In this sewing machine, mounting an auxiliary table on a free arm forms a flat bed portion.
However, in the aforementioned sewing machine, the auxiliary table to be mounted on the free arm has fixed dimensions, which results in that a working space of the flat bed portion is too small or large, for a specific workpiece, to make a user's operation for sewing the workpiece inconvenient.
A need thus exists to provide a sewing machine that has variable dimensions of a working space of a flat bed portion that is formed when an auxiliary table is mounted on a free arm.